Sheet laminate for solid oxide fuel cell, precursor for solid oxide fuel cell, apparatus for manufacturing sheet laminate for solid oxide fuel cell, and method for manufacturing sheet laminate for solid oxide fuel cell

ABSTRACT

The present specification relates to a sheet laminate for a solid oxide fuel cell, a precursor for a solid oxide fuel cell including the same, an apparatus for manufacturing a sheet laminate for a solid oxide fuel cell, and a method for manufacturing a sheet laminate for a solid oxide fuel cell.

TECHNICAL FIELD

This specification claims priority to and the benefit of Korean PatentApplication No. 10-2015-0082728 filed in the Korean IntellectualProperty Office on Jun. 11, 2015, the entire contents of which areincorporated herein by reference.

The present specification relates to a sheet laminate for a solid oxidefuel cell, a precursor for a solid oxide fuel cell comprising the same,an apparatus for manufacturing a sheet laminate for a solid oxide fuelcell, and a method for manufacturing a sheet laminate for a solid oxidefuel cell.

BACKGROUND ART

Recently, depletion of existing energy sources such as oil and coal hasbeen predicted, and interest in energy that can replace the energy isincreasing. A fuel cell as one of the alternative energy hasparticularly received attention due to high efficiency and merits suchthat pollutants such as NOx and SOx are not discharged and the used fuelis abundant.

The fuel cell is a power generation system that converts chemicalreaction energy of the fuel and an oxidizer into electric energy, andhydrogen and hydrocarbons such as methanol and butane as the fuel andoxygen as the oxidizer are representatively used.

In the fuel cell, there are a proton exchange membrane fuel cell(PEMFC), a direct methanol fuel cell (DMFC), a phosphoric acid fuel cell(PAFC), an alkaline fuel cell (AFC), a molten carbonate fuel cell(MCFC), a solid oxide fuel cell (SPFC), and the like.

DETAILED DESCRIPTION OF THE INVENTION Technical Problem

The present specification has been made in an effort to provide a sheetlaminate for a solid oxide fuel cell, a precursor for a solid oxide fuelcell including the same, an apparatus for manufacturing a sheet laminatefor a solid oxide fuel cell, and a method for manufacturing a sheetlaminate for a solid oxide fuel cell.

Technical Solution

An exemplary embodiment of the present specification provides a sheetlaminate for a solid oxide fuel cell including two or more sheetscontaining solid oxides and solvents, in which the sheet laminateincludes a first sheet containing a first solid oxide and a firstsolvent and a second sheet provided on the first sheet and containing asecond solid oxide and a second solvent and the specific gravity of thefirst solvent is higher than the specific gravity of the second solvent.

Another exemplary embodiment of the present specification provides aprecursor for a solid oxide fuel cell in which an anode, a solidelectrolyte membrane, and a cathode are sequentially provided, in whichat least one of the anode, the solid electrolyte membrane, and thecathode includes the sheet laminate.

Yet another exemplary embodiment of the present specification providesan apparatus for manufacturing a sheet laminate for a solid oxide fuelcell including: a coated member supplying unit; a sheet laminatecollecting unit; and two or more coaters that coat a coating compositioncontaining a solid oxide and a solvent on the surface of a coated memberproceeding from the coated member supplying unit to the sheet laminatecollecting unit to form a sheet laminate on the coated member, in whichthe two or more coaters include a first coater that supplies a coatingcomposition containing a first solid oxide and a first solvent to form afirst sheet and a second coater that supplies a coating compositioncontaining a second solid oxide and a second solvent to form a secondsheet on the first sheet, and the specific gravity of the first solventis higher than the specific gravity of the second solvent.

Still another exemplary embodiment of the present specification providesa method for manufacturing a sheet laminate for a solid oxide fuel cellincluding forming two or more sheets on a coated member by coating acoating composition containing a solid oxide and a solvent tomanufacture a sheet laminate, in which the forming of the two or moresheets includes forming a first sheet containing a first solid oxide anda first solvent and forming a second sheet provided on the first sheetand containing a second solid oxide and a second solvent, and thespecific gravity of the first solvent is higher than the specificgravity of the second solvent.

Advantageous Effects

According to the method for manufacturing the sheet laminate for thesolid oxide fuel cell of the present specification, it is possible toshorten a process as compared with a repeating process of sinteringafter single-layer coating.

Further, it is possible to prevent occurrence of bubbles betweeninterfaces, which may occur in a process of laminating a multilayersheet.

Further, it is possible to prevent defects caused by foreign materialsbetween interfaces, which may occur in a process of laminating amultilayer sheet.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a coating process of a first coater and a secondcoater of an apparatus for manufacturing a sheet laminate for a solidoxide fuel cell according to an exemplary embodiment of the presentspecification.

FIG. 2 is a scanning electron microscopic (SEM) image for cross sectionsof a first sheet and a second sheet of Example 1 of the presentspecification.

EXPLANATION OF REFERENCE NUMERALS AND SYMBOLS Best Mode

Hereinafter, exemplary embodiments of the present specification will bedescribed in detail.

The present specification provides a sheet laminate for a solid oxidefuel cell including two or more sheets containing solid oxides andsolvents, in which the sheet laminate includes a first sheet containinga first solid oxide and a first solvent and a second sheet provided onthe first sheet and containing a second solid oxide and a second solventand the specific gravity of the first solvent is higher than thespecific gravity of the second solvent.

The sheet laminate for the solid oxide fuel cell of the presentspecification includes two or more sheets containing solid oxides andsolvents. Particularly, the sheet laminate may be formed by laminatingtwo or more sheets containing solid oxides and solvents, respectively.

The sheet laminate may be formed by laminating two or more sheets andparticularly, the sheet laminate may be formed by laminating two to foursheets.

The two or more sheets may include a first sheet containing a firstsolid oxide and a first solvent and a second sheet provided on the firstsheet and containing a second solid oxide and a second solvent.

The two or more sheets may further include a third sheet provided on thesecond sheet and containing a third solid oxide and a third solvent.Particularly, the two or more sheets may include a first sheetcontaining a first solid oxide and a first solvent; a second sheetprovided on the first sheet and containing a second solid oxide and asecond solvent; and a third sheet provided on the second sheet andcontaining a third solid oxide and a third solvent.

The two or more sheets may further include a fourth sheet provided onthe third sheet and containing a fourth solid oxide and a fourthsolvent. Particularly, the two or more sheets may include a first sheetcontaining a first solid oxide and a first solvent; a second sheetprovided on the first sheet and containing a second solid oxide and asecond solvent; a third sheet provided on the second sheet andcontaining a third solid oxide and a third solvent; and a fourth sheetprovided on the third sheet and containing a fourth solid oxide and afourth solvent.

The two or more sheets may be green sheets for a solid oxide fuel cellin which two or more sheets are laminated for manufacturing the solidoxide fuel cell in which an anode, a solid electrolyte membrane, and acathode are sequentially included. Particularly, the two or more sheetsmay be a green sheet laminate of an anode and a solid electrolytemembrane; a green sheet laminate in which an anode, a solid electrolytemembrane, and a cathode are sequentially included; a green sheetlaminate of two or more anodes; a green sheet laminate of two or moresolid electrolyte membranes; or a green sheet laminate of two or morecathodes.

The green sheet means a film-like membrane which may be processed in anext process other than a complete end product.

In the present specification, the green sheet is coated with a coatingcomposition containing the solid oxide and the solvent to be dried in asheet form and means a semi-dried sheet capable of maintaining a sheetform while including some solvent.

A thickness of any one sheet of the two or more sheets may have variousthicknesses depending on a process step and/or a thickness of a desiredindividual sheet. Particularly, the thickness of any one sheet of thetwo or more sheets may be adjusted depending on a coating film which iscoated with the coating composition containing the solid oxide and thesolvent and not dried, a green sheet of which some of the solvent isremoved through a drying process, an electrode or an electrolytemembrane in which two or more relatively thin layers are laminated, athick film electrode formed by a relatively thick film, or the like. Ifnecessary, the thickness of any one sheet of the two or more sheets maybe 1 μm or more and 1,000 μm or less.

When any one sheet of the two or more sheets is an individual sheet formanufacturing the green sheet of the electrolyte membrane, the thicknessof the coating film before drying may be 5 μm or more and 1,000 μm orless.

When any one sheet of the two or more sheets is an individual sheet formanufacturing the green sheet of the electrolyte membrane, the thicknessof the green sheet of the electrolyte membrane after drying may be 1 μmor more and 800 μm or less.

When any one sheet of the two or more sheets is an individual sheet formanufacturing the green sheet of the anode, the thickness of the coatingfilm before drying may be 100 μm or more and 1,000 μm or less.

When any one sheet of the two or more sheets is an individual sheet formanufacturing the green sheet of the anode, the thickness of the greensheet of the solid electrolyte membrane after drying may be 100 μm ormore and 1,000 μm or less.

When any one sheet of the two or more sheets is an individual sheet formanufacturing the green sheet of the cathode, the thickness of thecoating film before drying may be 100 μm or more and 1,000 μm or less.

When any one sheet of the two or more sheets is an individual sheet formanufacturing the green sheet of the cathode, the thickness of the greensheet of the solid electrolyte membrane after drying may be 100 μm ormore and 1,000 μm or less.

Each of the two or more sheets contains the solid oxide and the solvent.Particularly, the individual sheets of the two or more sheetsindividually include the same or different solid oxides and solvents.

In the sheet laminate according to the exemplary embodiment of thepresent specification, the specific gravity of the solvent contained ina sheet relatively close to the ground may be higher than the specificgravity of the solvent contained in a sheet relatively farther from theground. In other words, the sheet relatively close to the ground means arelatively first manufactured sheet and the sheet relatively fartherfrom the ground means a relatively later manufactured sheet. In thiscase, there is an advantage in that the components of the adjacentsheets are not mixed.

In the sheet laminate according to the exemplary embodiment of thepresent specification, the specific gravity of the first solventcontained in the first sheet may be higher than the specific gravity ofthe second solvent contained in the second sheet provided on the firstsheet. In this case, there is an advantage in that the components of thefirst sheet and the second sheet are not mixed.

In the sheet laminate according to the exemplary embodiment of thepresent specification, the specific gravity of the first solventcontained in the first sheet may be higher than the specific gravity ofthe second solvent contained in the second sheet provided to contact thefirst sheet. In this case, there is an advantage in that the componentsof the first sheet and the second sheet are not mixed.

The solvent contained in the individual sheet of the two or more sheetsmay be a single solvent or a mixed solvent in which two or more solventsare mixed. In this case, when the solvent contained in the individualsheet is the mixed solvent, the specific gravity of the solventcontained in the individual sheet means the specific gravity of theentire mixed solvent.

If the solvent is selected so that the specific gravity of the solventcontained in the sheet relatively close to the ground is higher than thespecific gravity of the solvent contained in the sheet relativelyfarther from the ground, a type of solvent is not particularly limited,and the solvent may use a solvent which is generally used in the art.

For example, the solvent may include at least one of toluene (specificgravity: 0.867), propylene glycol monomethyl ether acetate (PGMEA)(specific gravity: 0.996), ethanol (specific gravity: 0.7893), methylethyl ketone (MEK) (specific gravity: 0.805), and propylene glycolmonomethyl ether (PGME) (specific gravity: 0.862).

A difference in the specific gravity between the solvent contained in asheet relatively close to the ground and the solvent contained in asheet provided to contact the sheet and relatively farther from theground may be 0.05 or more and 0.3 or less. In this case, there is anadvantage in that the solvents contained in different sheets are mixed.

In the sheet laminate according to the exemplary embodiment of thepresent specification, a difference in the specific gravity between thefirst solvent contained in the first sheet and the second solventcontained in the second sheet provided on the first sheet may be 0.05 ormore and 0.3 or less. In this case, there is an advantage in that thesolvents contained in different sheets are mixed.

In the sheet laminate according to the exemplary embodiment of thepresent specification, a difference in the specific gravity between thefirst solvent contained in the first sheet and the second solventcontained in the second sheet provided to contact the first sheet may be0.05 or more and 0.3 or less. In this case, there is an advantage inthat the solvents contained in the sheets contacting each other are notmixed.

Based on the total weight of the first sheet, the content of the firstsolvent may be 30 wt % or less.

Based on the total weight of the second sheet, the content of the secondsolvent may be 30 wt % or less.

When the two or more sheets, including a first sheet containing a firstsolid oxide and a first solvent and a second sheet provided on the firstsheet and containing a second solid oxide and a second solvent, furtherinclude a third sheet provided on the second sheet and containing athird solid oxide and a third solvent, the specific gravity of thesecond solvent may be higher than the specific gravity of the thirdsolvent. Particularly, a difference in the specific gravity between thefirst solvent and the second solvent may be 0.05 or more and 0.3 or lessand a difference in the specific gravity between the second solvent andthe third solvent may be 0.05 or more and 0.3 or less.

When the two or more sheets, including a first sheet containing a firstsolid oxide and a first solvent, a second sheet provided on the firstsheet and containing a second solid oxide and a second solvent and athird sheet provided on the second sheet and containing a third solidoxide and a third solvent, further include a fourth sheet provided onthe third sheet and containing a fourth solid oxide and a fourthsolvent, the specific gravity of the third solvent may be higher thanthe specific gravity of the fourth solvent. Particularly, a differencein the specific gravity between the first solvent and the second solventmay be 0.05 or more and 0.3 or less, a difference in the specificgravity between the second solvent and the third solvent may be 0.05 ormore and 0.3 or less, and a difference in the specific gravity betweenthe third solvent and the fourth solvent may be 0.05 or more and 0.3 orless.

In the present specification, the specific gravity means a ratio of theweight of water and the weight of a measuring material in the samevolume as the water, and represents that a material with the specificgravity of 1.00 or less is lighter than the water and a material withthe specific gravity of 1.00 or more is heavier than the water.

A constituent material of the solid oxide is not particularly limited aslong as the solid oxide is included in the anode, the solid electrolytemembrane, and the cathode of the solid oxide fuel cell according to apurpose.

The solid oxide may be two or more oxides selected from transitionmetals. Particularly, the solid oxide may be two or more oxides selectedfrom rare earth, a titanium group and a lanthanum group in the periodictable.

If at least one sheet of the two or more sheets is the sheet for theanode of the solid oxide fuel cell, the solid oxide included in thesheet for the anode may include at least one of yttria stabilizedzirconia oxide (YSZ: (Y₂O₃)_(x)(ZrO₂)_(1-x), x=0.05 to 0.15),scandinavian stabilized zirconium oxide (ScSZ: (Sc₂O₃)_(x)(ZrO₂)_(1-x),x=0.05 to 0.15)), samarium doped ceria (SDC: (Sm₂O₃)_(x)(CeO₂)_(1-x),x=0.02 to 0.4), and gadolinium doped ceria (GDC:(Gd₂O₃)_(x)(CeO₂)_(1-x), x=0.02 to 0.4).

If at least one sheet of the two or more sheets is the sheet for thesolid electrolyte membrane of the solid oxide fuel cell, the solid oxideincluded in the sheet for the solid electrolyte membrane may include atleast one of yttria stabilized zirconia oxide (YSZ:(Y₂O₃)_(x)(ZrO₂)_(1-x), x=0.05 to 0.15), scandinavian stabilizedzirconium oxide (ScSZ: (Sc₂O₃)_(x)(ZrO₂)_(1-x), x=0.05 to 0.15)),samarium doped ceria (SDC: (Sm₂O₃)_(x)(CeO₂)_(1-x), x=0.02 to 0.4), andgadolinium doped ceria (GDC: (Gd₂O₃)_(x)(CeO₂)_(1-x), x=0.02 to 0.4).

If the two or more sheets are the sheets for the cathode of the solidoxide fuel cell, the solid oxide included in the sheets for the cathodemay include at least one of lanthanum strontium cobalt ferrite (LSCF)and lanthanum strontium manganate (LSM).

The two or more sheets may further include plasticizers except for thesolid oxides and the solvents. The kind of plasticizer is notparticularly limited and plasticizers generally used in the art may beadopted, and for example, and the plasticizer may be dibutyl phthalate(DBP).

The present specification provides a precursor for a solid oxide fuelcell in which an anode, a solid electrolyte membrane, and a cathode aresequentially provided, in which at least one of the anode, the solidelectrolyte membrane, and the cathode includes the sheet laminate.

In the present specification, the precursor for the solid oxide fuelcell means a state before the solid oxide fuel cell is completelymanufactured, and particularly, a state in which the solid oxide fuelcell in which the anode, the solid electrolyte membrane, and the cathodeare sequentially provided can be formed through a sintering process. Inother words, the precursor for the solid oxide fuel cell of the presentspecification includes one or more layers in which the solvent is notcompletely removed and means a state in which the solid oxide fuel cellin which the anode, the solid electrolyte membrane, and the cathode aresequentially provided can be formed through a sintering process.

In the precursor for the solid oxide fuel cell, the solid electrolytemembrane includes two or more solid electrolyte membranes and the two ormore solid electrolyte membranes may include the sheet laminate.

In the precursor for the solid oxide fuel cell, the anode and the solidelectrolyte membrane provided on the anode may include the sheetlaminate.

In the precursor for the solid oxide fuel cell, when the solidelectrolyte membrane includes two or more solid electrolyte membranes,the anode and the two or more solid electrolyte membranes provided onthe anode may include the sheet laminate.

In the precursor for the solid oxide fuel cell, the anode, a solidelectrolyte membrane provided on the anode, and a cathode provided onthe solid electrolyte membrane may include the sheet laminate.

In the precursor for the solid oxide fuel cell, when the solidelectrolyte membrane includes two or more solid electrolyte membranes,the anode, the two or more solid electrolyte membranes provided on theanode, and the cathode provided on the solid electrolyte membrane mayinclude the sheet laminate.

The present specification provides a solid oxide fuel cell in which theprecursor for the solid oxide fuel cell is sintered.

In the solid oxide fuel cell, an anode, a solid electrolyte membrane,and a cathode may be sequentially provided.

The present specification provides a cell module including the solidoxide fuel cell as a unit cell.

The cell module may include a stack including unit cells including thesolid oxide fuel cell and a separator provided between the unit cells; afuel supplying unit supplying the fuel to the stack; and an oxidizersupplying unit supplying an oxidizer to the stack.

The cell module may be particularly used as power of an electricvehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle oran electric power storage device.

The present specification provides an apparatus for manufacturing asheet laminate for a solid oxide fuel cell including a coated membersupplying unit, a sheet laminate collecting unit, and two or morecoaters that coat a coating composition containing a solid oxide and asolvent on the surface of a coated member proceeding from the coatedmember supplying unit to the sheet laminate collecting unit to form asheet laminate on the coated member, in which the two or more coatersinclude a first coater that supplies a coating composition containing afirst solid oxide and a first solvent to form a first sheet and a secondcoater that supplies a coating composition containing a second solidoxide and a second solvent to form a second sheet on the first sheet,and the specific gravity of the first solvent is higher than thespecific gravity of the second solvent.

In the apparatus for manufacturing the sheet laminate for the solidoxide fuel cell of the present specification, description for the sameor similar configuration as or to the sheet laminate for the solid oxidefuel cell may cite those described above.

The two or more coaters may include a first coater that supplies acoating composition containing a first solid oxide and a first solventto form a first sheet and a second coater that supplies a coatingcomposition containing a second solid oxide and a second solvent to forma second sheet on the first sheet.

The two or more coaters may include a first coater that supplies acoating composition containing a first solid oxide and a first solventto form a first sheet, a second coater that supplies a coatingcomposition containing a second solid oxide and a second solvent to forma second sheet on the first sheet, and a third coater that supplies acoating composition containing a third solid oxide and a third solventto form a third sheet on the second sheet.

The two or more coaters may include a first coater that supplies acoating composition containing a first solid oxide and a first solventto form a first sheet, a second coater that supplies a coatingcomposition containing a second solid oxide and a second solvent to forma second sheet on the first sheet, a third coater that supplies acoating composition containing a third solid oxide and a third solventto form a third sheet on the second sheet, and a fourth coater thatsupplies a coating composition containing a fourth solid oxide and afourth solvent to form a fourth sheet on the third sheet.

Each of the two or more coaters may include a supplying unit thatsupplies a coating composition containing a solid oxide and a solvent toform a sheet and a thickness adjusting portion that adjusts a thicknessof the sheet.

The first coater may include a first supplying unit that supplies acoating composition containing a first solid oxide and a first solventto form a first sheet and a first thickness adjusting portion thatadjusts a thickness of the first sheet.

The second coater may include a second supplying unit that supplies acoating composition containing a second solid oxide and a second solventto form a second sheet on the first sheet and a second thicknessadjusting portion that adjusts a thickness of the second sheet.

The third coater may include a third supplying unit that supplies acoating composition containing a third solid oxide and a third solventto form a third sheet on the second sheet and a third thicknessadjusting portion that adjusts a thickness of the third sheet.

The fourth coater may include a fourth supplying unit that supplies acoating composition containing a fourth solid oxide and a fourth solventto form a fourth sheet on the third sheet and a fourth thicknessadjusting portion that adjusts a thickness of the fourth sheet.

The two or more coaters may be spaced apart from each other on onesurface of the coated member.

The two or more coaters include any one coater and the other coateradjacent to any one coater and may be spaced apart from each other at adistance considering a process from one point where the coated member orthe sheet laminate contacts any one coater to one point where the coatedmember or the sheet laminate contacts the other coater.

A material of the coated member is not particularly limited so long asthe material supports the sheet laminate and is easily removed later,but may adopt a material which is generally used in the art.

The apparatus for manufacturing the sheet laminate for the solid oxidefuel cell of the present specification may further include a drying unitpositioned between the two or more coaters and the sheet laminatecollecting unit.

The drying unit may dry the sheet laminate in which the coating of thetwo or more sheets is completed.

The drying unit is a unit to maintain a shape of the sheet by partiallyremoving each solvent contained in the individual sheet of the sheetlaminate in which the coating of the two or more sheets is completed.

The content of the solvent contained in the individual sheet of thesheet laminate dried by the drying unit may be 0.1 wt % or more and 10wt % or less based on the total weight of the solvent contained in theindividual sheet before drying.

A temperature of the drying unit may be 60° C. or more and 90° C. orless.

The apparatus for manufacturing the sheet laminate for the solid oxidefuel cell of the present specification may further include a green sheetsupplying unit; and a pressing roll that presses a green sheet and thedried sheet laminate so that the green sheet supplied from the greensheet supplying unit contacts the surface of the dried sheet laminate.

The apparatus for manufacturing the sheet laminate for the solid oxidefuel cell may include one or more sintering units.

The apparatus for manufacturing the sheet laminate for the solid oxidefuel cell of the present specification may further include a drying unitpositioned between the two or more coaters and the sheet laminatecollecting unit and a sintering unit positioned between the drying unitand the sheet laminate collecting unit.

The sintering unit may sinter the dried sheet laminate at once. In thiscase, the temperature of the sintering unit may be 1,000° C. or more and1,500° C. or less.

When the apparatus for manufacturing the sheet laminate for the solidoxide fuel cell further includes a green sheet supplying unit; and apressing roll that presses a green sheet and the dried sheet laminate sothat the green sheet supplied from the green sheet supplying unitcontacts the surface of the dried sheet laminate, the sintering unit maybe positioned between the pressing roll and the sheet laminatecollecting unit to sinter the dried sheet laminate and the green sheettogether. In this case, the temperature of the sintering unit may be1,000° C. or more and 1,500° C. or less.

When the apparatus for manufacturing the sheet laminate for the solidoxide fuel cell further includes a green sheet supplying unit; and apressing roll that presses a green sheet and the dried sheet laminate sothat the green sheet supplied from the green sheet supplying unitcontacts the surface of the dried sheet laminate, the sintering unit mayinclude a first sintering unit provided between the drying unit and thepressing roll and a second sintering unit provided between the pressingroll and the sheet laminate collecting unit.

The first sintering unit sinters the dried sheet laminate at once andthe temperature of the first sintering unit may be 1,000° C. or more and1,500° C. or less.

The second sintering unit sinters the green sheet provided on thesintered sheet laminate and in this case, the temperature of the secondsintering unit may be 1,000° C. or more and 1,500° C. or less.

The apparatus for manufacturing the sheet laminate for the solid oxidefuel cell of the present specification may further include a coatedmember removing unit that removes the coated member from the dried sheetlaminate or the sintered sheet laminate.

The coated member removing unit may be provided between the drying unitand the pressing roll. In this case, before the green sheet is laminatedby the pressing roll, the coated member is removed and the green sheetmay be laminated on at least one of a surface from which the coatedmember of the dried sheet laminate is removed and an opposite surface tothe surface from which the coated member of the dried sheet laminate isremoved.

The coated member removing unit may be provided between the firstsintering unit and the pressing roll. In this case, before the greensheet is laminated by the pressing roll, the coated member is removedand the green sheet may be laminated on at least one of a surface fromwhich the coated member of the sintered sheet laminate is removed and anopposite surface to the surface from which the coated member of thesintered sheet laminate is removed.

The coated member removing unit may be provided between the sinteringunit and the sheet laminate collecting unit.

The present specification provides a method for manufacturing a sheetlaminate for a solid oxide fuel cell including forming two or moresheets on a coated member by coating a coating composition containing asolid oxide and a solvent to manufacture a sheet laminate, in which theforming of the two or more sheets includes forming a first sheetcontaining a first solid oxide and a first solvent and forming a secondsheet provided on the first sheet and containing a second solid oxideand a second solvent, and the specific gravity of the first solvent ishigher than the specific gravity of the second solvent.

In the method for manufacturing the sheet laminate for the solid oxidefuel cell of the present specification, description for the same orsimilar configuration as or to the sheet laminate for the solid oxidefuel cell and the method for manufacturing the same may cite thosedescribed above.

The forming of the two or more sheets may include forming a first sheetcontaining a first solid oxide and a first solvent and forming a secondsheet provided on the first sheet and containing a second solid oxideand a second solvent.

The forming of the two or more sheets may include forming a first sheetcontaining a first solid oxide and a first solvent; forming a secondsheet provided on the first sheet and containing a second solid oxideand a second solvent; and forming a third sheet provided on the secondsheet and containing a third solid oxide and a third solvent.

The forming of the two or more sheets may include forming a first sheetcontaining a first solid oxide and a first solvent; forming a secondsheet provided on the first sheet and containing a second solid oxideand a second solvent; forming a third sheet provided on the second sheetand containing a third solid oxide and a third solvent; and forming afourth sheet provided on the third sheet and containing a fourth solidoxide and a fourth solvent.

The method for manufacturing the sheet laminate for the solid oxide fuelcell of the present specification may further include drying themanufactured sheet laminate.

The method for manufacturing the sheet laminate for the solid oxide fuelcell of the present specification may further include sintering thedried sheet laminate.

The method for manufacturing the sheet laminate for the solid oxide fuelcell of the present specification may further include laminating thegreen sheet on the surface of the dried sheet laminate.

The method for manufacturing the sheet laminate for the solid oxide fuelcell of the present specification may further include removing thecoated member before the laminating. In this case, in the laminatedgreen sheet, the green sheet may be laminated on at least one of asurface from which the coated member of the dried sheet laminate isremoved and an opposite surface to the surface from which the coatedmember of the dried sheet laminate is removed.

The method for manufacturing the sheet laminate for the solid oxide fuelcell of the present specification may further include laminating thegreen sheet on the surface of the dried sheet laminate and sintering thesheet laminate on which the green sheet is laminated.

The method for manufacturing the sheet laminate for the solid oxide fuelcell of the present specification may further include laminating thegreen sheet on the surface of the sintered sheet laminate; and sinteringthe green sheet.

The method for manufacturing the sheet laminate for the solid oxide fuelcell of the present specification may further include removing thecoated member before the laminating. In this case, in the laminatedgreen sheet, the green sheet may be laminated on at least one of asurface from which the coated member of the sintered sheet laminate isremoved and an opposite surface to the surface from which the coatedmember of the sintered sheet laminate is removed.

In order to manufacture the solid oxide fuel cell, a process of makingand laminating three types of layers of a cathode (an air electrode), ananode (a fuel electrode), and a solid electrolyte membrane is required.

Generally, the fuel electrode is manufactured by using a method such aspressing and then the solid electrolyte membrane and the air electrodeare sequentially laminated on the fuel electrode by a method such as dipcoating and screen printing. In this case, a subsequent film may belaminated only through a sintering process before each layer islaminated.

Meanwhile, the layers of the cathode, the solid electrolyte membrane andthe anode may be respectively processed and laminated in a sheet formand simultaneously sintered. In this case, in the process of laminatingeach sheet, bubbles between the sheets occur or foreign materials areinput between the sheets to cause defects.

The method for manufacturing the sheet laminate for the solid oxide fuelcell of the present specification is characterized by coating amultilayer at once without the drying process or the sintering processbetween the coating processes of the respective layers.

In the method for manufacturing the sheet laminate for the solid oxidefuel cell of the present specification, since the two or more coatedlayers are dried and sintered at once, it is possible to shorten aprocess as compared with a repeating process of sintering the coatedsingle layer.

Further, it is possible to prevent occurrence of bubbles betweeninterfaces, which may occur in a process of laminating a multilayersheet.

Further, it is possible to prevent defects caused by foreign materialsbetween interfaces, which may occur in a process of laminating amultilayer sheet.

Hereinafter, the present specification will be described in more detailthrough Examples. However, the following Examples are just to exemplifythe present specification and the present specification is not limitedthereto.

EXAMPLE Example 1

On a substrate, a composition for a first sheet containing 6.2 g (50 wt%) of gadolinium doped ceria (GDC), 1.2 g (9.7 wt %) of DISPERBYK-112 asa dispersant, 0.1 g (0.8 wt %) of DBP as a plasticizer, 1.5 g (12.1 wt%) of SOKEN LRRS001 as a binder solution, and 3.4 g (PGMEA, 27.4 wt %)of propylene glycol monomethyl ether acetate as a solvent was coated bya first coater. In this case, a first sheet coated by the first coaterwas adjusted to 50 μm.

The first sheet was not dried, and then on the first sheet, acomposition for a second sheet including 20 g (40 wt %) of yttriastabilized zirconium oxide (YSZ), 1.34 g (2.7 wt %) of BYK112 as adispersant, 0.20 g (0.4 wt %) of DBP as a plasticizer, 5 g (10 wt %) ofSOKEN LRRS001 as a binder solution, and 23.5 g (47 wt %) of toluene as asolvent was coated by using a second coater, and then a manufacturedsheet laminate was dried at 70° C. for 5 minutes. In this case, thesecond sheet coated by the second coater was adjusted to 100 μm, andthicknesses of the first sheet and the second sheet of the dried sheetlaminate were 7 μm like a SEM image illustrated in FIG. 2, respectively.

On the second sheet of the dried sheet laminate, an anode green sheetincluding yttria stabilized zirconium oxide with a thickness of 400 μmwas laminated and then the sheet laminate was sintered together with theanode green sheet at 1350° C.

A printed member of the sintered sheet laminate was removed, a cathodegreen sheet containing lantanium strontium cobalt ferrite (LSCF) waslaminated on a surface from which the printed member was removed, andthen the cathode green sheet was sintered at 1,000° C. to manufacture asolid oxide fuel cell.

1. A sheet laminate for a solid oxide fuel cell including two or moresheets containing solid oxides and solvents, the sheet laminatecomprising: a first sheet containing a first solid oxide and a firstsolvent; and a second sheet provided on the first sheet and containing asecond solid oxide and a second solvent, wherein the specific gravity ofthe first solvent is higher than the specific gravity of the secondsolvent.
 2. The sheet laminate of claim 1, wherein a difference inspecific gravity between the first solvent and the second solvent is0.05 or more and 0.3 or less.
 3. The sheet laminate of claim 1, whereinthe content of the first solvent is 30 wt % or less based on the totalweight of the first sheet.
 4. The sheet laminate of claim 1, wherein thecontent of the second solvent is 30 wt % or less based on the totalweight of the second sheet.
 5. (canceled)
 6. (canceled)
 7. The sheetlaminate of claim 1, wherein the solvent includes at least one oftoluene (specific gravity: 0.867), propylene glycol monomethyl etheracetate (PGMEA) (specific gravity: 0.996), ethanol (specific gravity:0.7893), methyl ethyl ketone (MEK) (specific gravity: 0.805), andpropylene glycol monomethyl ether (PGME) (specific gravity: 0.862). 8.(canceled)
 9. A precursor for a solid oxide fuel cell in which an anode,a solid electrolyte membrane, and a cathode are sequentially included,wherein at least one of the anode, the solid electrolyte membrane, andthe cathode includes the sheet laminate according to claim
 1. 10.-14.(canceled)
 15. An apparatus for manufacturing a sheet laminate for asolid oxide fuel cell, the apparatus comprising: a coated membersupplying unit; a sheet laminate collecting unit; and two or morecoaters that coat a coating composition containing a solid oxide and asolvent on the surface of a coated member proceeding from the coatedmember supplying unit to the sheet laminate collecting unit to form asheet laminate on the coated member, wherein the two or more coatersinclude a first coater that supplies a coating composition containing afirst solid oxide and a first solvent to form a first sheet and a secondcoater that supplies a coating composition containing a second solidoxide and a second solvent to form a second sheet on the first sheet,and the specific gravity of the first solvent is higher than thespecific gravity of the second solvent.
 16. The apparatus of claim 15,wherein the first coater includes a first supplying unit that suppliesthe coating composition containing the first solid oxide and the firstsolvent to form the first sheet and a first thickness adjusting portionthat adjusts a thickness of the first sheet, and the second coaterincludes a second supplying unit that supplies the coating compositioncontaining the second solid oxide and the second solvent to form thesecond sheet on the first sheet and a second thickness adjusting portionthat adjusts a thickness of the second sheet.
 17. The apparatus of claim15, wherein the two or more coaters are spaced apart from each other onone surface of the coated member.
 18. The apparatus of claim 15, whereina difference in specific gravity between the first solvent and thesecond solvent is 0.05 or more and 0.3 or less.
 19. (canceled) 20.(canceled)
 21. The apparatus of claim 15, further comprising: a dryingunit positioned between the two or more coaters and the sheet laminatecollecting unit.
 22. The apparatus of claim 21, further comprising: agreen sheet supplying unit; and a pressing roll that presses the greensheet and the dried sheet laminate so that the green sheet supplied fromthe green sheet supplying unit contacts the surface of the dried sheetlaminate.
 23. The apparatus of claim 21, further comprising: a sinteringunit positioned between the drying unit and the sheet laminatecollecting unit.
 24. A method for manufacturing a sheet laminate for asolid oxide fuel cell, the method comprising: forming two or more sheetson a coated member by coating a coating composition containing a solidoxide and a solvent to manufacture a sheet laminate, wherein the formingof the two or more sheets includes forming a first sheet containing afirst solid oxide and a first solvent and forming a second sheetprovided on the first sheet and containing a second solid oxide and asecond solvent, and the specific gravity of the first solvent is higherthan the specific gravity of the second solvent.
 25. The method of claim24, wherein a difference in specific gravity between the first solventand the second solvent is 0.05 or more and 0.3 or less.
 26. (canceled)27. (canceled)
 28. The method of claim 24, further comprising: dryingthe manufactured sheet laminate.
 29. The method of claim 28, furthercomprising: sintering the dried sheet laminate.
 30. The method of claim28, further comprising: laminating the green sheet on the surface of thedried sheet laminate.
 31. The method of claim 30, further comprising:sintering the sheet laminate on which the green sheet is laminated. 32.The method of claim 29, further comprising: laminating a green sheet onthe surface of the sintered sheet laminate; and sintering the greensheet.